Heater system for oil engines



March 12, 192-9. H. E. BRIGGS I 1,704,934

HEATER SYSTEM FOR OIL ENGINES f v Filed Feb. 17, 1923 s Sheets-Sheet 1 g a I? 2/ 1 1%- l 22 22 24 a:

BY I

ATTORNEY-S March 12, 1929. H. E RIGGs 1,704,934

HEATER SYSTEM FOR OIL ENGINES Filed Feb. 1'7, 1923 5 Sheets-Sheet 2 Q 27 2 3 H as 0 3 I v 2/ F1q- L-v 18 33 INVENTOR.

W flfi/ezx 5 5/9/0051 ATTORNEYS.

March 12, 1929. H. E. amass 1,704,934

HEATER SYSTEM FOR OIL ENGINES rma Feb. 17, 1925 Sheets-Sheet 3 F1q. F 2! Z3 22 2 I l {N7 4 I l [as 9 F 7 ea 1 '23 I mmmu FIE-T 8 2/7 22/ INVENTORQ HHKK) 5 Bk/GGJ.

ATTORNEYS.

March 12, 1929; H, E, RI G 1,704,934 v HEATER SYSTEM FOR OIL ENGINE$ Filed Feb. 17. 1923 5 Sheets-Sheet 4 PIE E! FIG-l. 1D

IIIIIIII'III, III "III ll VIII/7,, 79 a1 a; as

INVENTOR. HHERKE .Bf/GGS.

AITORNEYS.

Much 12, 1929.

5 Sheets-Sheet Filed Feb. 17. 1923 n\ Mi 3: :1 J i Q a "m w g; E

. u 4 i 9!. b2 Q. R a O I 2\ R 4 E Patented Mar. 12 1929.

HARRY n. caress, or ANDERSON, INDIANA.

HEATER SYSTEM FGR OIL ENGINES.

Application filed February This invention relates to internal combustion engines of the semi-Diesel type which are adapted to burn crude oils and the like.

The chie'lf object of the invention is to provide a cylinder of an internal combus-' tion engine of the cl'iaracter described with a heating plug which is heated from an external source of energy, which energy is introduced into the plug to provide heat therein and raise the plug temperature to that desired and necessary for the ignition of the combustible mixture supplied to the engine cylinder.

Another object of the invention is to provide automatically operable means, whereby the externally energized plug will be automatically energized and (lo-energized in the operation of the engine and by means operable by said engine.

Another important object of the inven tion is to associate the automatic control with the igniting plug in such a manner that the auton'iatic control does not directly control the operation of said plug but re motely controls the same.

Another object of the invention is to construct theplug in such a manner that it may be associated with other plu s or other cylinders in the same engine; so that all the plugs can be operated at their maximum capacity with a minimum initial cost and maintenance cost.

Another object of the invention is to provide the engine with a plug or plugs, and suitably connect the same to a source of energy which source of energy may be oi three types. I

The chief features of the invention consists in the means for accomplishing all of the foregoing objects.

The full nature of the invention will be understood from theaceompanying draw lugs and the following description and claims. 2

In the drawings. Fig. 1 is a diagramn'iatic view of a plurality of plugs connected in parallel and energized by an alternating current source of energy with the addition of an automatically operable switch for reinotely controlling the connection between said plugs, and said source of alternating current. g. 2 is a similar view of substautially the same parts, except that the alt rnating current source of energy is re placed by a direct current source of energy.

17, 1923. Serial No. 619,6'16.

Fig. 8 is a view similar to Fig. 1, except that the automatically operable switch directly controls the connection between the plugs and the source of alternating current. Fig. 4: is a View similar to Fig. 3, except that the alternating current source of energy is replaced by a direct source of energy. Fig. 5 is a view similar to Fig. 8, except that the automatically controlled switch is eliminated. Fig. '6 is a View similar to Fig. 5, except that the alternating current source of energyis replaced by a direct current source of energy. Fig. 7 is a diagrammatic View of a plurality of plugs similar to those shown in Figs. 1 to 6 inclusive, but herein shown connected in series instead of in parallel. Fig.8 is a diagrammatic view of a similar number of similar plugs showing the same connected in a series-parallel relation. Fig. 9 is an enlarged transverse sectional view 01. a single cylinder of an in ternal combustion engine of the character described showing the same provided with a heating plug. Fig. 10 is a similar view, but is taken at right angles to the plane of Fig. 9. Fig, 11 is a longitudinal sectional view of one form of heating plug. Fig. 12 is an endview of the same. Fig. 13 is a transverse sectional View taken on the line 1313 of Fig. 11 and in the direction of the arrows; Fig. 14 is the fuel pump construction of an internal combustion engine of the character described with parts in section to show other oarts in detail. Fig. 15 is a side elevation o the governorand fuel pump of an internal combustion engine of the character described with parts in section and parts broken away to show other parts in detail. Fig. 16 is a longitudinal-sectional view of another form of heating plug similar to that illustrated in Figs. 11, '12 and 13. Fig. 17is an enlarged end view ofthe plug shown in Fig. 16.

' In Fig. 1 of the drawings there is illustrated a plurality of heating elements hereinafter termed heating plugs which have a heating portion 20 and a securing portion 21. Each plug is provided with suitable electrical connections and in Figs. 1 to 6 inclusive, said plugs are shown connected in parallel by the parallel lines 22 and 23 and individually controlled by the switches 19. The lines 22 are connected together to a line 2 1-, and thelines 23 are connected together by a line 25.' The line 24 is connected to one terminal 26 of a switch having the handle .27

and blades 28 and .29. The line is connectcd to the opposite terminal 31 through a relay switch having the switch points v the lines 39 and l0 to the secondary winding 4-1 of a transformer having the primary winding 4-2. The primary winding 42 is connected to the source of alternating current- 43 by the wires tet and 45.

Included in the double pole switchvconstruction is a pair of auxiliary contacts 46 and 17. The contact 47 is connected by a line 48 to a pair of parallel connected contacts 49 of a switch connection. These contacts 49 are preferaliily movable and are adapted to engage a pair of preferably stationary contacts 50 likewise connected in parallel which are connected to a relay 51 by means of a line 52. The 51 has an armature or stem 53 which carries the switch bridging bar 32 hereinbefore described. The other terminal of the relay 51 is connected by the line 54 to the other terminal 46 of the main switch construction.-

A sliding shaft 55 carries a collar 56 having a groove 57 therein. Associated with the shaft 55 are the weighted centrifugal governor levers 58 which terminate adjacent the collar 56 and in the groove 57 and .serve to reciprocate the shaft 55 in accordance with the speed of the engine. The shaft 55 actuates a pivoted yoke 59 which terminates in an actuating portion 60. The actuating portion (30 is adapted to engage either of the movable contacts 49 to move the same into engagement with the adjacent stationary contact 50. Thus at a relatively high speed, the lever 59 will cause one contact 4-9 to engage the adjacent contact 50 and close a cirwith the relay 51, and thereby energize the relay. The relay elevates the armature 53 and maintains said armature in the elevated position, which corresponds to the closed circuit position of the switch, including the bridging bar 32 and the contacts 30. These are connected to the double throw main switch, and herein said contacts 30 are connccted to the terminal 31 of said switch and the line 25 respectively by the lines 61 and 33, both being connected to the line 25 hereinbefore described. 7

When the handle 27 is positioned in the upper position so that the blades 28. and 29 engage the switch points 34 and 35, current is supplied from the alternator through the transformer to the switch points 341: and 35 and therea ter is conducted by the lines 24, and 25 to the heating plugs. The aforesaid constitutes the manual operation and is gen erally used in starting. After the engine has obtained its normal speed, the switch handle 27 is moved to the lowermost position so as to engage the contacts 46, 47, 26 and 31. lVhen in this position, current is supplied to the terminal plugs from the alternator by way of the transformer only at such time as the switch points 30 are bridged by the bridging bar 32, and this can only be accomplished by the relay 51 being energized, which in turn can only be accom-- plished by the closing of a circuit, including one of the movable switch members 49 and I the adjacent stationary member 50. The closure of either of these switches controlling the relay circuit is accomplished only when the speed of the engine has been reduced sulliciently so as to cause the lever 59 to be moved into actuating position in one direction, or when the speed of the engine has increased to such an extent that the lever has been moved sufficiently into the opposite direction. Light load conditions of an engine of the character described permit the en ine to run at an excessive rate of speed, and when running under light load conditions, the heat retained in the engine is not sutlicient to ignite the diminished fuel supply and thereafter poor ignition results as a general rule. But with the present construct-ion, such poor ignition does not result, because when the light load condition occurs, the circuit through the-relay 51 will be closed, which in turn closes the switch controlled by the relay to supply the heat ing plugswith energy from the alternator 4-3. Herein in order to prevent excessive arcing at the contacts 30 and bridging bar 32, the same are immersed in an oil receptacle 63 containing the usual arc-diminishing or dampening mineral oil 64.

In Fig. 2 of the drawings the lines 23 of the individually controllable plugs are shown grounded at 123 and the line 25 is shown grounded at 123, thereby completing the circuit from the line 23 through the ground connection to the line 25 and the circuit is thereafter substantially the same as that hereinbefore described for parts illustrated in Fig. 1, with this exception, the lines it) and 39 in Fig. 2 are connected to a source of energy, but in this instance instead of being connected to the transformer construction indicated by the numerals 4:1 and 42, and the alternator 4:3 as shown in Fig. 1, said lines are connected to a storage battery 65. The storage battery 65, therefore, provides a source of direct current energy and thus replaces or may be substituted vior the source of alternating current 43 mdieated. It is to be noted that the alternator may be a high tension alternator or inay be a low tension alternator, and in tne latter event the transformer having the windings 41 and 42 maybe eliminated. it is likewise to be noted thatit a suitable source oi alternating or direct currentis provided at a normal voltage, to-wit, 110, 220 or 550, the lines 40 and 39 may be connected directly thereto, as in the-ordinary service application. I

lnorder to make the engine unit sellcontaincd as well as fully automatic, as hereinbe'tore described, a direct current generator G6 is provided which is driven by the engine through suitable power connections and said generator is connected by the line 6? to one terminal of the battery and is connected by the line (38 to the other termi nal of the battery 65 through the relay 69. The reverse current relay prevents the battery from discharging through the generator at such times as the battery is not under load, but permits the generator to discharge 4 0 the battery even though the main double pole, double throw switch, or the relay operable switch, or the governor operable switch be open, thus charging the battery 65. At light loads the generator 66 will also assume part of the heating load and assist the battery 65 or carry most of the load imposed upon the circuit by closing the same through the several switches and the heating plugs. Fig. 2, therefore, illustrates a self-contained and automatically and remotely controlled construction. The arrangement oi the circuit described in Fig. 2 is identical with that illustrated and descr .d. with reference to Fig. 1, and said circuits are provided with the same refercncenumerals.

In 3 the construction is very similar to that shown in Fig. l, but herein the feature of remote control has'oeen eliminated. in this term of the invention similar numerals indicate like parts. There is this change, or, the relay and relay-operable switch hereto and the lines 52 and 48 as seciated with the automatically controlled parallel switches are connected directly to the line 25 and the switch point 31 direct.

in Fig. at it will be noted that the construction illustrated is substantially identi cal with that illustrated in Fig. 2, except that the remote control relay operable switch has been eliminated and the automatically cont-rolled switch is directly associated with the source of energy as-hereto'i'ore described with reference to Fig. 3. Herein the lines. :32 4L8 are connected to the lines 25 andsingle switch point'81 in the same relation as described with reference to Flg. 3. Fig. 1

ditiers from Fig. 8 in the same manner that Fig. 2 diliers from F1g. l, to-wit, there is herein illustrated a source of direct current,

whereas in Fig. 3 there is illustrated a source 01 alternating current and the remarks heretofore made with reference to the source of current illustrated in Figs. 1 and 2 apply equally to the sources of current shown in Figs. 3 and at.

In Fig. 5 there is illustrated a still further i si nplificd form of the invention, and in this form of the invention the automatic control eliminated, as well as the remote control. This :torm out the invention is essentially manually operable, andherein there is il-' lustr'ated a double pole single throw switch having the handle 127 and the switch points 138 and 137 and the switch points 134 anding plugs when the handle 127 is moved to close the circuit by bridging the gaps between the switch contacts 138 and 13d and 137 and 135.

In Fig. 6 the plugs therein illustrated are connected in the identical. manner shown in Figs. 2 and l and the feeder lines 24- and 25 from said plugs are connected to the terminals 135 of the switch construction in a manner identical to that illustrated in Fig. 5 and hereinbetore described. The lines 40 and 39 are similarly connected. to the switch points 138 and 13'? atone endand-to a source of direct current identical with that hereinberore described with reference to Figs. 2 and 4'. It will again be noted that Fig. 6

only differs from Fig. 5 in the same manner that Fig. t differs from Fig. 3,and Fig. 2 differs trom F 1g. 1. It Will be noted that Figs. 1 and 2 diiler from Figs. 3 and 4- by the addition of the remote control and mechanism, while Figs. '3 and l ditl er from Figs. 5 and 6 by the additional omission of the au toinatically operable switch, reducing the invention in Figs. 5and 6 to a straight manually operable circuit. If desired, the same circuit shown in Figs. 5 and 6 may be modified by the substitution of a relay controlled circuit, such as shown in Figs. 1 and 2, and the relay thereof could be included in a circuit comprising the same or another source of energy and a manually operable switch substantially similar to that shown in'Figs. 5 and 6, or said switch may be a single pole,

blll'OlV switch, thus breaking the rein the construction illustrated in lay circuit in but one place instead of two places and simultaneously. WVhen the same can be secured. in view of the forms of the invention illustrated in Figs. 1 to 6 inclusive, the foregoing suggested modifications of tie invention will be readily understood by those skilled in the art to which the invention applies and further illustration thereof is believed needless.

In Fig. 7 the plugs -21 are supplied by the feeder lines 121 and 125. The feeder lines 124 and 125, however, are connected to each other through the plugs 20-21. It will. be remembered that the lines 24: and to 6 inclusive were connected to each other through the plugs by a parallel construction including the plug terminal lines 22 and 23. Herein the plug terminal lines are designated by the numerals 122and 121, and said lines are connected together so as to form a series connection, so that the feeder lines 12st and 125 are connected together and the plugs by a series connection. It is to be noted that the aforesaid connection may be substituted for the connections shown in Figs. 1 to 6 inclusive, and such a change from a parallel to a series connection is to be construed as an equivalent construction, the sole function of such a construction being to permit the use of suitable resistance elements in the plug proper, the detailed construction of which will be hereinafter described. It will be sometimes desirable to use a low voltage high amperage relation, and when such-is the case, the parallel construction shown in Figs. 5 or 0 will be utilized. When, however, a high voltage, low amperage is available, the construction shown in Fig. 7 is the preferable connection of the plugs.

.In Fig. 8 the plug feeder lines are indicated by the numerals 22d and 225, and in this instance the several. plugs 20 and 21 arev connected in seriesparallel relation. The lines 322 to two of the plugs are connected together and to the line 22st. The other terminals of the same plugs have the line 221 connected to the line 222 of an adjacent plug through a switch 219, and the other terminals of the adjacent plugs are connected by the lines 321 to the line Thus, a series-parallel connection of the plugs is secured, and it may be desirable un der certain conditions to utilize a series parallel connection, preferably, however, either a series connection or the parallel connection will be utilized.

In Figs; 9 and 10. there illustrated a. conventional form of: cylinder con struction and the associated parts. In said figures, illustrates a cylinder block pro vided with a head 71 having a fuel passage 72 therein, which is enlarged to form an ignition chamber 73. A cap or cover 74; is provided with a chamber 75, and said chame hers 73 and 75 form a complete ignition chamber. Extending into the chamber 73 is the heating plug, and particularly the portion 20 thereof, said plug being secured to the head 71 by means of the body portion 21. The particular construction of the plug will be hereinafter described. Positioned in the cap 7 1 is a fuel nozzle 76, which nozzle is adapted to discharge fuel upon the body portion 20, and as herein shown may also be adapted to discharge fuel directly on to the piston head slidably supported in the cylinder walls 70 by the fuel passing through the passage 72. The nozzle 76 is supplied with fuel from the supply line 77, which herein is shown provided with a relief valve 7 8. The supply line 77 connected to a suitable fuel pump, hereinafter to be described.

In Figs. 11, 12 and 13 there is illustrated one form of the heater plug, and in said figures, the plug body is hollowed out as at 79 and a seat 80 is provided at the closed end of said portion. The body portion 21 has an externally tapered and threaded portion 81, whereby said plug is rigidly secured in the cylinder head 71, as illustrated in Fig. 9. The body portion is illustrated as cut away at 82 and at 83 and grooved at 84L adjacent to the enlarged opening 83. Extending axially through the hollowed body is an insulating core 85 which is adapted to stand up under high temperatures, particularly within the range of 500 to 1,500 degrees Fahrenheit. The commercial product known as Lava satisfies this condition and will approximately withstand 2,000 degrees before disintegrating. The surface 86 of the core 85, is threaded and positioned in said threads, is a wire 87, which constitutes a resistance unit. Said wire terminates adjacent the free end in a leader portion 88 positioned in a slot 89 which communicates with an axial hole 90 through the insulator body portion 85 and the axial opening 90 receives the connection 91. The space between the core carrying the resistance unit and the wall of the chambers 79-82 is herein shown filled with an insulating compound 92. The end of the core 85 opposite from the slotted end 89 is herein illustrated as provided withthr'ee projecting portions 93 which are receivable by the chan'iber 82 and; serve to center the outer end of the core 85, whereas the other end of the core 85 is centered by reason of the conical end 80. The wire'87and the leader 91 are brought out through holes 94, see Fig. 12, cut in an insib .lating plug or disk 95 seated in the enlar ed of the axial opening in the 11. w

body. The insulated disk or plate 95 is retained in position by means of the spring clip ring 96 seated in the groove 84. The disk 95 supports a pair of terminal posts 97 and these each are secured to one of the heating unit terminal wires 87 or 91 by means of the nut 98 while the external connector' 99 is secured to said terminal post or stud 97 by means of the thumb nut 100. The construction shown in Figs. 11, 12 and 13 constitute one form of heating plug which might be employed.

Reference will now be had to Figs. 14 and 15 wherein a fuel pump construction is illustrated and the automatically. operable switch construction is likewise illustrated. In said figures the framework is indicated generally by the numeral .101, and the same slidabl supports the fuel valve construction 1IlCl1- cated generally by the numeral 102. The fuel valve construction is adjusted by the supporting lever 103 and is actuated by the roller supporting yoke 104 carrying the roller 105. The roller 105 is adapted to engagethe cam 106 supported upon the shaft or sleeve 55, which it will be remembered is rotatable with the main shaft 107 and slidably mounted thereon. The sliding movement, it will likewise be remembered, is imparted by the governor construction illus trated in Fig. 15 and diagrammatically illustrated in Figs. 1 to 4 inclusive. The lever 59 is herein shown as a. clamp member, see Fig. 14, pivotally supported at 108, and the opposite end of the lever is connected to the actuator 60, which is herein illustrated as carried by the sliding rod 109.

The governor operable switch, it will be remembered, includes the movable contacts 49 and the stationary contacts 50, which stationary contacts 50 are connected in parallel as well as the contacts 49 which are similarly connected in parallel. The adjustingscrews 110 adjust the position of the stationary contacts 50. A suitable housing 111 supports the entire switch construction, and the same may be filled with an arc-resisting and quenching fluid, such as mineral oil and the like.

The rod 109 extends into a snap switch construction indicated generally by the numeral 112 and an actuating portion 113 is associated with said snap switch construction and with the yokeleve'r 59 so as to transmit movement from said yoke lever 59 to the actuating member 60 with a quick make-andbreak movement.

The connection between the yoke-shaped pivoted lever 59 and the actuating member 113 is as follows: The sleeve which carries the cams 106 and grooved collar 56 also carries a member 114. Said member 114 engages one side of a ball thrust bearing construction 115, which is. directly connected to the yoke lever 59, as shown in Figs. 14 and 15. The pivoted yoke lever 59 terminates at 116 in a yoke portion which is suitably secured to an extension 117 of a spring supporting member 113. Associated with the extension 117 and directly connected thereto is the map switch actuating member 113 hereinbefore described. A stationary support 140 receives a threaded shaft 141 which carries upon one end a hand wheel 142 and upon the other end a spring seat member 143 which is slidably supported upon rods 144 secured at one end to the supporting member 118 hereinbefore mentioned. The other ends of said rods are secured to the spring retainer 145 and seated upon said rods between the seats 143 and 145 is a coiled spring 146. The rod 141 has a threaded connect-ion with the spring seat 143. e

From the foregoing construction it will be noted that when the hand wheel 142 is turned, the tension of the spring 146 will be increased or decreased, and with said increase or decrease in tension, there will be a corresponding movement of the, pivoted lever 59, and said movement is transmitted through the ball thrust bearing 115 to the sleeve construction, and in turn to the spring controlled weighted levers 58. The. recultant structure, therefore, is that the governor construction may be loaded or unloaded by means of the aforesaid third sprin adjustment. For instance, it has been experimen tally determined that the full'load speed of the hereinbefore described engine is 250 R. P. M. and the speeds at other loads are as follows: 254R. P. M. at load; 251 R. P. M. at load and 260 R. P. M. at 4 load and 263 R. P. M. at no load, and that at 10% overload, the R. P. M. is 247, the loading of the governor springs may be varied so as to shift the range of speeds. At the speed corresponding to no load, the position of the weighted levers is fully extended. Thus, by increasing the effect of the third spring transmitted to thecam sleeve construction herein illustrated, the governor position at noload speed can be changed, and correspondingly the fuel supplied thereto will be changed in proportion.

Under no load condition, the engine receives a smaller supply of'fuel' than under full load conditions, and to insure successful operation of the engineat this no load speed, the foregoing automatic construction has been associated therewith so that the heating plugs are energized to ignite the small supply of fuel furnished. "Certainty of ignition at no load condition heretofore has been impossible because under no load conditions the amount of heat generated has not been Sufficient to keep the piston heated to the pro-per temperature to ignite .the fuel when the same impinges thereon. At no load with the present additions to the. construction, all of the fuel will always be ignited by reason of other and a modified form of the heater the heated plug construction being energized at said no load.

In starting, of course, the speed of the engine is zero and rapidly rises. Under such conditions the governor levers are in their innermost position and are not distented. The cam sleeve is in its correspond ing position so as to sup Jly the engine with a maximum amount of mi. Since the engine is cold, the fuel discharged into the cylinders must be ignited by same external means, and this external means herein constitutes the heated plug. 1 7

It sometimes happens that one of the cylinders of the engine for some unknown rea son suddenly stops firing when the engine is operating under a or full load condition. l/Vhen this occurs, thespeed of the engine immediately drops below the minimum rated full load speed of the governor, so that this condition is comparable to the starting condition hereinbefore described. Thereupon the plugs automatically will become energized. and will insure complete ignition in all the cylinders until such time the speed of the engine increases to full load speed, whereupon the plugs will be deenergized. It will be noted that the switch indicated generally by the numerals 49 and 50 is automatically operable by the governor construction and preferably with a -quick make-and-break movement toprevent arcing, and, therefore, since a two-position and parallel switch construction is provided, the engine will be provided with externally heated ignition means under low speeds and at excessive speeds or at all speeds other than full load speeds.

The operation of the device has been described in detail, and a general summary need only be herein given. The manually operable switch indicated in the several Figures, 1 to4 inclusive, is closed at starting,

and preferably in the upper position until. the engine has been brought to speed and the load applied. Thereafter, the switch is opened and closed in the lower position which throws the heating plugs over on to an automatically controlled circuit. If desired, however, this throw-over arrange ,ment may be eliminated and the switch be but a single throw switch, such as illustrated in Figs. 5 and 6; and when such is the case, the starting is accomplished automatically,

'sincein Figs. 1 and 2 the governor actuated switch operates the relay to close the plug circuit; while in Figs. 3 and 4 the governor actuated switch closes" the circuit directly through the heating plugs.

-In Figs. 16 and 17 there is illustrated anplug, and in said figures the plug body comprises a tubular portion 170 having a closed end 171 with a conical seat 172 therein. The

tubular portion 170 at its opposite end ter minates inan externally'threaded and tapered portion 173, which is enlarged at 174 to form a tool-receiving portion, and herein said portion 174 is shown as hexagonal in form.' The portions 173 and 174iare hollowed out at 175 and externally threaded as at 170. Extending axially through the hollowed body is an insulating core 185. This insulating body or core is adapted to stand up under high temperatures, particularly within 500 to 1000 degrees Fahrenheit. Such material is r a commercial product known as Lava which will readily withstand a temperature of 2000 degrees. The

surface 186 of the core is externally threaded, and herein the threaded portion 186 differs from the portion 86 of the previously described modification, that is, the former is a double thread. The wire 187 is positioned in one of said threads and runs from one end of the thread to the opposite end, and thereupon passes through the core by passing through the opening 189, which provides a communication from one of the threads to the other thread. The wire 18? thus passes down one thread. and returns up the other thread. The end of the core 185 opposite the communication 189 is enlarged as at 188 and is threaded externally to be receivable by the threads 176 of the plug wall. Thus the core at this end is centered within the tubular heater body, and the other'end of the core is centered by reason of the conical end 180 engaging the conical portion 172 of the plug body. The wire 187 is brought out through the openings 19st in' the enlarged portion 183. L The enlarged portion 1823 supports a pair of terminal posts 197 which have a threaded engagement It will be noted that the modified form of the heater plug shown in Figs. 16 and 17 constitutes the simplest form of the invention which may be made. It is to be understood that the metallic body portion 170 is preferably formed of a metal having peculiar properties, such as low specific heat and high resistance to conduction of heat which have been found to be desirable in a heating unit which is subjected to the high temperatures found in a crude oil engine under normal operation.

It has been found that in a multi-cylinder engine one or more cylinders do not require as much attention as others. The

switches 19 and 219 permit of considerable latitude in control that may be .not only desirable but necessary at times.

Although the invention has been described in reat detail in the fore oin s ecifica-.

b b D tions, such a. detailed description is to be considered only as illustrative in character. Many modifications have been suggested in the foregoing some of which have been il lnstrated as well as described, and these modifications as well as those which will readily suggest themselves to those skilled in the art to which this invention applies are all considered to be within the broad purview of the appended claims, which herein read on all figures, and particularly Figs. 2, 8, 9 and 15.

The invention claimed is:

1. The combination with a crude or fuel oil engine, of source of electrical energy, an electrically heated igniter forsaid engine, an engine controlled switch, and a double throw switch for connecting said igniter directly with said source of electrical energy or through said engine controlled switch.

2. The combination with a crude or fuel oil engine, of a source .of electrical energy comprising a storage battery, a generator driven by said engine and connected to the battery for charging the same, relay means controlling the battery and generator connection, an electrically heated igniter for said engine, an engine controlled switch, and

a double throw switch -for connecting said igniter directly with said source of electrical energy or through said engine controlled switch.

3. The combination with a crude or fuel oil engine, of an engine controlled switch,

an electrically heated igniter for said engine, a switch for controlling said igniter and remotely controlled by said engine controlled switch, a source of electrical energy for said electrically heated igniter co1nprising a storage battery, a generator driven by said engine and connected to-the battery for a rela controllin said rela controlled switch and controlled by said governor operable switch, a source ofelectrical energy comprising a storage battery, generator driven by said engine and connected to the battery for charging the same, and a relay means controlling the battery and generator connection.

5. In a crude or fuel oil engine having a fly-ball governor operable thereby and for controlling the same, an electrically heated igniter, and a switch for controlling said igniter, the combination of a reciprocable shaft for actuating the switch, a lever ac-' tuatahleby the governor construction and operatively connected to the shaft, and a loading spring for said shaft and lever.

6. A device as defined by claim 5, characterized by the'addition of an adjustable arrangement for varying the loading of said spring.

In witness whereof, I have hereunto aflixed my signature.

HARRY E. BRIGGS. 

